Grindstone.



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INVENTQR, WITNESSES; JQHNSTURTRIDGEDREADON,

Attorney Patente'd Jan. 4, 1910.

JOHN STUBTRIDG-E DREADON', OF MI'I'ITAI, NORTHERN WAIROA, NEW ZEALAND.

Specification of Letters Patent.

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Patented Jan. 4, 1910.

Kpplication filed November 20, 1908. Serial N 0. 463,632.

To all whom it may concern:

Be it known that I,.JOHN STURTRIDGE DREADON, subject of the King of Great- Britain, residing at Mititai, Northern Wairoa. New Zealand, have invented a new and useful Improved Gri-ndlng Device; and I do hereby declare the following to be a full,

time, but which may also be used in the ordinary way.

According .to this invention, sultable grinding material, which may be of stone orof other approved nature, is secured within the periphery of two wheels mounted upon a shaft adjacent to each other, in such a manner that the adjacent surfaces of the grinding material will be in juxtaposition and revolve together. These surfaces are tapered inward so that the two together form a wedge shaped opening into which the tapered edge of a tool is adapted to fit in order that both faces of the tool may be ground.

()ne wheel is fixed on the shaft, while the other is made free to slide to and fro on it, while being arranged to rotate therewith. Means are provided whereby the position of the movable wheel may be varied with regard to the fixed wheel' in order that the width of the opening between the grinding faces may be regulated.

The construction of the invention is illustrated in the accompanying drawings, in which,

Figure 1 is a side elevation. Fig. 2 an end elevation, and Fig. 3' a cross sectional elevation of the grinding device.

The shaft a is carried horizontally in suitable bearings upon standards 6 and rovided with any approved means by .wli it may be revolved. Upon the shaft are mounted the wheels and Z,the Wheel 0 being firmly keyed to the shaft, while'the wheel d is mounted upon a feather key in order that it may be moved to and fro along the shaft. A spring e is placed around the shaft between the two wheels, and bears outward against the bosses thereof in order ich Y to normally press thetwo wheels apart. A collar f is mounted upon the shaft a outside the wheel (1 by means of which the Wheel 03 may be kept at any desired distance apart from the wheel 0.

The outer periphery of each wheel is formed with a side flange g on its outer edge, so as thus to provide areceptacle to receive the grinding material h which may be of any approved material, such as blocks of stone or emery compositions, shaped to fit around the wheels periphery. The adjacent surfaces of the grinding material carried on both wheels will thus be in juxtaposition, and the distance between them may be regulated by varying the position of the wheel d upon the shaft. These adjacent surfaces will be tapered as shown in the drawirfgsfso as to provide the wedge shaped opening between them into which the edge of the tool to be ground may be placed so that it may be acted upon by the grinding surfaces on both sides.

Set screws y' are screwed through the side flanges g and bear against the grinding material 72. By means of these screws, any wear upon the inner grinding faces may be compensated for and the opening between such faces, adjusted.

The outer peripheries of the grinding material h may be used for grinding in the usual manner.

What I do claim as my invention, and de sire to secure by Letters Patent, is,

In a grinding device, a pair of relativelyseparable wheels each having an edge flange,- blocks of grinding material secured around the periphery of each wheel, with those on one wheel normally in juxtaposition to those on the other, and set screws at intervals passing through the flange of each wheel and bearing against the blocks of grinding material, in combination with means connected with both wheels for rotating the same in unison.

In testimony whereof, I have signed this specification 1n the presence of two subscribing witnesses.

.lOllN STURTRIDGE EREADON.

Witnesses:

E. GRUBE-SMITH, E. F. CoUn'rNEY; 

